Process of charging lead-peroxid-zinc storage batteries.



i UDOLF ZIEGENBERG,

Agpilcmion imguat S, I

iilli: amza'led, a Em f ch all

902s: (23115 as an on" the elestric y 91 tign are s;

t 'n u w 2110 v a-m 11L LEV/1115.55 1

' malts Mm pa ilOlllCm L luring '4. tlloned 1t is im firmly adherent aclclnlamed s0 OF BEELIV,

-11 33G. EATTEEBZEEJ.

Fawn-sad Fab. w, 190% plates may cause direct shoxt @ircuia, awards, under the mfluence oi the -l ll easily from lms zmc-plaias 301L316 0f the call thus ihfizs shalt sircuit and. .emg en'tirely (iLSEQiVEiL The free acid, has still the fm'iher osgestmnable result that a large prop-0x503 01 1'" cinimt'sd by curran'b i in the us acid at saame in s or AS1103 sly (ls,- tc. su h extan' a that in proyor- 510i; to themwical ua nialty 01" zinc, up to of the latter plecip @566. by the cur ram; is soon ai an. ELllS n dissolved. The zins dissalv lug the previous discharge is thus in vleisly msovered, and in *omains & large which further L we was psainfluence of the lib an man.- ner lwwevar thatfoff well 3 Malian, tbs regular char ng of the p03 is not lniorfored mm 01' injura l and. especially that the innial mitv of? the batiery retained.

Hi9.- c i (he pmduction or u ,l the use of a di -v.. 0i density which, after .arge, atill. gives surplus 0f and "which does pmzluce goo-d (lapasit, It thus follows ally l' t chalgin 0f tl a elemezl j which 2. l. fulfil pmctiw st 1 fla ella (some other earnest favor 314s hal favorable lasts Well which pmdum as, Vlf Zcizneutral 01' a 1 mile-Ll su lien 05 zinc l n in ti. ,lso u-qedas thaposilive elm the decom- 'lesitian of lame sul; inc ul- LiZ'TlC acid is s nply so me (l that at the pcsitiv'e Qlc'ilflile a portiun equal t0 the quantity 0f zinc precipitated by the current is eonlinugusly dissolved by said freed acid H3915 latter is neutralized and at the same lime esb zinc supplied is the balk itselu whim thus permnently ossesses the same ion. The applicaiion 05 this meththe aha-wing of the lead-zinc lo ite'z-y is imposslbi- 1'- clle leggsn at lesad permzicl is used therein as the positive electrode. Otherwise the positive lead pemzdxl plates have to be charged separately which "with particular pounds are Z1I1C-OXMl and zinc-hydrate which All in addition to other practical disadvantages would involve a prohibitive increase in the cost oi the cbargin operation.

if for charging the bath an ordinary neutral solution of zinc sulfate is used the chargis favorable at the commencement but as with the increasing decomposition of the zinc sulfate the freed acid enters more into action, the previously mentioned objections to the charging recess result. Moreover care must thus e taken to obtain a continuous neutralization of the acid freed independently oi the positive plate. This is obtained according to the present invention in the follotving manner. The positive and negative plates are suspended in a slightly acidulated, that is to say, almost neutral solution of zinc sulfate, and in addition to these plates Inetallic zinc insertions-having no electrical connection with the other circuit are also suspended in the charging bath, said zinc insertions haviru the form of plates or other suitably shaped zinc pieces. l or this purpose even small zinc pieces chips or the like placed in suitable perforated vessels of glass, or porcelain may he used. 'l he free acid then dissolves said zinc pieces in re oi'tion to its liberation and is thus neutra lZQt in the same manner. Instead of using metallic Zincior this purpose certain Zinc compounds which, together with the liberated acid produce zinc sulfate, vmay be-equally applied advantage. Such corniiissolve even more easily than metallic zinc and their use is articularry advantageous in combination w th the further method of. recovering zincdescribed in the specification of a further application made concurrently herewith. The said zinc compounds are added is surplus to the charging bath and neutralize the acid according as the latter becomes liberated during the charging. This continuous neutralization of the acid need not however necessarily talre place in the charging bath itself but may with advantage be efl'ected in a separate or special receptacle communicating with said bath. The substances required for the neutralization viz. metallic Zinc or zinc compounds are placed in said auxiliary receptacles and dissolved preferably by means of heat. 1 or the urpose of obtaining a good mixture with the iquid in the main charging vessel said liquid may be put into circulation by any suitable means. This may be done either mechanically by a stirring device of suitable construction or by compressed air introduced into the charging bath through a pipe system provided with openings similarly to a heating coil. Bv causing the liquid to circulatess aforesaid the gasbubbles at the zinc-plates iormed during charging are at the same time continuously removed, whereby the uni-- I 1 l r eraser.

formity and density of the zinc precipitate is greatly increased.

In carrying this particular charging process in o oractice, vessels serving for charging are filled at the commencement with a neutral or slightly acidulated saturated solution of zinc sulfate diluted, for instance, with twice its volume of water and the charging is efi'ccted in such vessels without particular neutralization. The size of the vessels is so chosen that the acid developed during the charging of a set of plates is not sufficient to allow the above mentioned unfavorable effects to appear to any considerable extent, that is to say, the charging is carried out in a loath so large (i. e. with so much liquid) that the free acid developed is uniformly distributed, the acid being thus highly diluted to reduce injurious eiiects. At the end of the charging the free acid is neutralizedas stated above. When thecharged plates are removed a quantity of metallic zinc or preferably zinc oxid or zinc hydrate which maybe easily determined by practice, is placed inthe charging bath and dissolved therein. This is suitably effected by means of heat and may be easily arried out by blowing in steam. Should the charging bath become too hot for charging the positive lead-peroxid plates the temperature may be reduced to the required degree by blowing in cold air.

The bath is then again in the same condition as before the first charging that is to say, the requisite zinc compounds have been added to the bath and the acid liberated by the first charge has been neutralized.

,The present charging process is characteruse by the following novel features, firstly the charging takes piace in a different liquid to the discharging in order to permit aregwlar simultaneous charging 0 0th the positive and negative plates while preserving the tery, and secondly the acid liberated by the simultaneous charging of the positive and negative lates is permanently neutralized by specie means W ich do not interfere. un-

favorably with the charging process in any ters Patent, is

1. The process of charging lead-pcroxid 'zlnc storage batteries, consisting 1n placing the positive and negative plates, normally disch'argeable in sulfuric acid, in a substantially neutral solution of zinc sulfate, and in maintaining the charging bath in a substantially neutral condition by inserting therein zinc, not in electrical connection with the plates, substantially'as described.

2. The process or" charging lead-peroxidzinc storage batteries, consisting in placing the positive and negative plates, normally high capacity peculiar to this kind of batize firmed from the plates, and in agitafing may dischargeable in sulfuric acid, in a, substaw 1 in testimony whereof L have signed my tialiy neutral solution 0f zinc sulfate, andin l name as this specification in the presence of inserting zinc in the same solution, snfisepa twflsubscxibing witnesses ED338155 ZIEGENBERG 5 liquid to prcvmots intimate, mixmire' and, :0 Witnessss:

-' remove bubblgs fmm the negative piatas, OTTO KYBURG,

substantiaiiy as desoribeda i ARTHUR Lmzrmnmw. 

